Phases and Phase Transitions of Block Copolymers

Spontaneous formation of ordered structures from amphiphilic molecules has attracted tremendous attentions in the last decades. Among the many different amphiphilic systems, block copolymers with their rich phase behaviour and ordering transitions have become a paradigm for the study of structural self-assembly. For the simplest case of diblock copolymers, which are linear polymers composed of two different sub-chains (A and B blocks), a variety of ordered bulk phases, including lamellae, hexagonally-packed cylinders, body-centered-cubic spheres and a bicontinuous network structure called gyroid, are observed. Theoretical studies of block copolymer phase behavior have been mostly within mean-field approximation, which is capable of describing many of the observed phases. In my talk I will present our studies of the kinetic pathways of the order-order transitions.